Results 1 -
6 of
6
The leganet system: Freshness-aware transaction routing in a database cluster
, 2007
"... ... databases can be update-intensive and must remain autonomous. In this paper, we describe the Leganet system which performs freshness-aware transaction routing in a database cluster. We use multi-master replication and relaxed replica freshness to increase load balancing. Our transaction routing ..."
Abstract
-
Cited by 10 (4 self)
- Add to MetaCart
(Show Context)
... databases can be update-intensive and must remain autonomous. In this paper, we describe the Leganet system which performs freshness-aware transaction routing in a database cluster. We use multi-master replication and relaxed replica freshness to increase load balancing. Our transaction routing takes into account freshness requirements of queries at the relation level and uses a cost function that takes into account the cluster load and the cost to refresh replicas to the required level. We implemented the Leganet prototype on an 11-node Linux cluster running Oracle8i. Using experimentation and emulation up to 128 nodes, our validation based on the TPC-C benchmark demonstrates the performance benefits of our approach.
DTR: Distributed Transaction Routing in a Large Scale Network
- HIGH PERFORMANCE COMPUTING FOR COMPUTATIONAL SCIENCE
, 2008
"... Grid systems provide access to huge storage and computing resources at large scale. While they have been mainly dedicated to scientific computing for years, grids are now considered as a viable solution for hosting data-intensive applications. To this end, databases are replicated over the grid in o ..."
Abstract
-
Cited by 4 (3 self)
- Add to MetaCart
(Show Context)
Grid systems provide access to huge storage and computing resources at large scale. While they have been mainly dedicated to scientific computing for years, grids are now considered as a viable solution for hosting data-intensive applications. To this end, databases are replicated over the grid in order to achieve high availability and fast transaction processing thanks to parallelism. However, achieving both fast and consistent data access on such architectures is challenging at many points. In particular, centralized control is prohibited because of its vulnerability and lack of efficiency at large scale. In this article, we propose a novel solution for the distributed control of transaction routing in a large scale network. We leverage a cluster-oriented routing solution with a fully distributed approach that uses a large scale distributed directory to handle routing metadata. Moreover, we demonstrate the feasibility of our implementation through experimentation: results expose linear scale-up, and transaction routing time is fast enough to make our solution eligible for update intensive applications such as world wide online booking.
Fine-grained Refresh Strategies for Managing Replication in Database Clusters
- In VLDB Wshp. on Design, Implementation and Deployment of Database Replication
, 2005
"... Relaxing replica freshness has been exploited in database clusters to optimize load balancing. In this paper, we propose to support... ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
Relaxing replica freshness has been exploited in database clusters to optimize load balancing. In this paper, we propose to support...
Replica Refresh Strategies in a Database Cluster
- in "Journées Bases de Données Avancées (BDA05
, 2005
"... We consider the use of a cluster system for managing autonomous databases. In order to improve the performance of read-only queries, we study the impact of refresh strategies on the query response time. Assuming mono-master lazy replication, we propose a model for refresh strategies and a workload g ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
(Show Context)
We consider the use of a cluster system for managing autonomous databases. In order to improve the performance of read-only queries, we study the impact of refresh strategies on the query response time. Assuming mono-master lazy replication, we propose a model for refresh strategies and a workload generator which allows for testing refresh strategies against various application types. We provide an experimental validation based on our prototype Refresco. The results show that the choice of the best strategy depends not only on the workload intensity (update and query frequencies), but also on the workload conflict rate (ratio of queries conflicting with running update transactions) and on the level of freshness required by transactions.
Data Quality Management in a Database Cluster with Lazy Replication
"... We consider the use of a database cluster with lazy replication. In this context, controlling the quality of replicated data based on users' requirements is important to improve performance. However, existing approaches are limited to a particular aspect of data quality. In this paper, we propo ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
We consider the use of a database cluster with lazy replication. In this context, controlling the quality of replicated data based on users' requirements is important to improve performance. However, existing approaches are limited to a particular aspect of data quality. In this paper, we propose a general model of data quality which makes the di#erence between "freshness" and "validity" of data. Data quality is expressed through divergence measures from the data with perfect quality. Users can thus specify the minimum level of quality for their queries. This information can be exploited to optimize query load balancing. We implemented our approach in our Refresco prototype. The results show that freshness control can help increase query throughput significantly. They also show significant improvement when freshness requirements are specified at the relation level rather than at the database level.
Database Replication in Large Scale Systems: Optimizing the Number of Replicas
"... In distributed systems, replication is used for ensuring availability and increasing performances. However, the heavy workload of distributed systems such as web2.0 applications or Global Distribution Systems, limits the benefit of replication if its degree (i.e., the number of replicas) is not cont ..."
Abstract
- Add to MetaCart
(Show Context)
In distributed systems, replication is used for ensuring availability and increasing performances. However, the heavy workload of distributed systems such as web2.0 applications or Global Distribution Systems, limits the benefit of replication if its degree (i.e., the number of replicas) is not controlled. Since every replica must perform all updates eventually, there is a point beyond which adding more replicas does not increase the throughput, because every replica is saturated by applying updates. Moreover, if the replication degree exceeds the optimal threshold, the useless replica would generate an overhead due to extra communication messages. In this paper, we propose a suitable replication management solution in order to reduce useless replicas. To this end, we define two mathematical models which approximate the appropriate number of replicas to achieve a given level of performance. Moreover, we demonstrate the feasibility of our replication management model through simulation. The results expose the effectiveness of our models and their accuracy. 1.
